//package com.lmq.interfaces;// interfaces/Sealed.java
//// (c)2021 MindView LLC: see Copyright.txt
//// We make no guarantees that this code is fit for any purpose.
//// Visit http://OnJava8.com for more book information.
//// {NewFeature} Since JDK 17
//
//sealed class Base permits D1, D2 {}
//
//final class D1 extends Base {}
//final class D2 extends Base {}
//// Illegal:
//// final class D3 extends Base {}
